Force mac address updates for slaves
Force mac address updates for slaves

When using VirtualBox as a provider, "slaves" had the same MAC as first network adapter in "master",
which was causing issues with networking. Now MAC will be randomly created.
loles/solar,pigmej/solar,loles/solar,pigmej/solar,zen/solar,openstack/solar,Mirantis/solar,zen/solar,Mirantis/solar,Mirantis/solar,zen/solar,loles/solar,openstack/solar,loles/solar,pigmej/solar,zen/solar,openstack/solar,Mirantis/solar